There seems to be a fundamental confusion on this thread about how proper names work.
The name of my country is the United States of America. How about, because of the partisan rancor that characterizes the country, I say it shouldn’t be called “United.” (That could, after all, be confusing to people.) So, I declare the country is now named States of America. YOU CAN’T DO THAT.
The title of the Bible, conventionally, in English, is Holy Bible. It makes just as much sense to criticize someone’s reference to a book title for using a “pretentious” adjective as it does to criticize someone’s reference to the United States as inaccurate for using the adjective “united.” It isn’t an adjective in that usage, it’s part of a name. Same thing with the proper noun, God’s Word. If you don’t think the Bible is “God’s,” it’s irrelevant to the conventional use of the proper noun. If you think the Big Island in Hawaii should really be called the “Medium-Sized Island,” too bad, so sad. That isn’t its name and your opinion about how appropriate its name is has zero relevance to the way people are going to continue using its name to refer to its namesake.